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(1) Field of the Invention
The invention concerns an optical waveguide.
(2) Description of the Related art including information discussed
under 37 CFR 1.97 and 1.98
Radiation polymerization devices in the form of optical illuminating arrangements with coupled flexible optical waveguides have already been known for a relatively long time both in industry and also in dentistry; see in that respect German laid-open applications DE-A1 30 09 171.5 and DE-A1 40 14 363.5, and utility model No G 94 00 445.5.
The radiation sources used for the radiation polymerization devices are either tungsten-halogen lamps, high-pressure xenon lamps or medium-pressure or high-pressure mercury lamps. In dentistry, it is predominantly light radiation in the blue spectral range, that is to say in the range of 400 nm less than xcex less than 500 nm that is used for the polymerization of filling materials (so-called composite materials), while for hardening industrial adhesives with radiation it is mostly UV-radiation in the wavelength range of 250 nm less than xcex less than 400 nm that is used. Both conventional glass fiber bundles or bundles of plastic fibers but also the liquid optical waveguides which have now been known for about 20 years can be coupled to the radiation source, as the flexible optical waveguides. The liquid optical waveguides can transmit both blue light and also UV-radiation with a high level of efficiency, in contrast to the glass fiber bundles.
Application of the radiation to the monomer is almost always controlled in respect of time by way of an adjustable timer, in which respect either the lamp is switched on for a defined time or, in the case of a continuously operated radiation source such as for example a mercury lamp, the light flow is opened by a shutter (light barrier) for a defined time, with the shutter being controlled by the timer. Triggering of the radiation dose to be applied is almost always effected either by way of a hand switch or by way of a foot switch, that is to say a closing device which functions galvanically. In the case of fiber bundle waveguides when used in dental practice use is made of both hand switches at the light exit end of the optical waveguide, and also foot switches. When liquid optical waveguides are used in dental practice, it is exclusively foot switches that are used, because, by virtue of their lower degree of flexibility and their low level of axial twistability, liquid optical waveguides all have a handle or handpiece which in the form of a rotatable tube. Thus the use of a galvanically functioning hand switch on that rotatable tube is technically burdensome and complicated because it is to be possible to actuate the hand switch in all rotational positions of the rotary tube.
The object of the invention is to provide an optical waveguide having a hand switch, which satisfies the specified requirements and which in particular is easy and economically advantageous to operate.
That object is attained by an optical waveguide as set forth in claim 1. Further developments of the hand switch according to the invention are described in the appendant claims.
The optical waveguide according to the invention, with hand switch, is suitable in particular for use in relation to liquid optical waveguides in dental practice for hardening fillings. However it also has advantages in terms of technical industrial uses of the liquid optical waveguide for hardening adhesives, in which the optical waveguide is guided by hand (for example when xe2x80x9csolderingxe2x80x9d boards with optical adhesives). The novel hand switch can be used not only for liquid optical waveguides but also waveguides made up of fiber bundles although they are particularly advantageous for liquid optical waveguides.